SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e16e1d7c914d7113ac45355f6f6685518c0ce7da8ebb94db4b409c7da7ee772a' 
  AND token = 'LKWCUtj0ufL0NIzKfwt1SPQSvMTMASo690BmieLgqtM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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