SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '661ff4465254d40f62ab022418d9ad510adf2c903280cd837352d793657e63e8' 
  AND token = 'TWbOTB1UpbsijugASxCuftn/qo1XjqVErfvB9SNe1qo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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