SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ed22b591ad8daadc8a45d1c289c99d4587988bd9f30d720b9632b2ea21f51c48' 
  AND token = 'fpem+fCbQECn/3Q7T8Rv97W3NVmEqZ5f3sHpqHowQC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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