SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0dbe7564222324a879c0873b79d237440f44a4a0955b72c943ea2e69335a1fc7' 
  AND token = 'm+r0+f8ZMuG3TQjuXpP5Hr2NrbGkhhtmDVEaqyHtiVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00298

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}