SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce18faf4485136b94521b8e802a397652da333810fbcc9a04e887e89fe127571' 
  AND token = 'q4AOYqj1ufSS/vxh/7JitZ7T8pIltrjVzpHjNBq8LB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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