SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c61d0dbf1515439f37239bc3c9f68e7281d140826ff31a15bbdc13a4d5151887' 
  AND token = 'rIm+3Xx1UDonaD8T/nrKlfCApyyoz2rxLqxQlS7bPyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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