SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c59bf2b0bf141c90f23e1502fcead233fd66c333915840a6c73556aa6fe1922c' 
  AND token = 'jkM2CGatMtxYW8WBk04IIBu32tmK7RJI5FJqp29Hpfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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