SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ca08429ac5452a018262b09dbb2cadcdd15fd77a4134b3b4aae34e34ddeb23c' 
  AND token = 'BgDlYqCQS/QBaR/vhLwQk4mTwkmFrn3qH5pB6HHQTMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}