SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '567b38d50f04756fc12afa212dd8bb04a9be7db1176ec701f3c2e9326846f758' 
  AND token = 'sPaD+NshsLyBlM3bqvJhIL//f6Ez+QjbNUP4UkRKc6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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