SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1529e0865c6dcaf70f33d2fa9182ba6cb54a986f276c6ca4b7f5bac6e5043b18' 
  AND token = 'Fb9KVuuuqDG35OStclw6QAdQA/w5hmmU/kmsQvG3sKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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