SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbbd615b237cc25a9d03b6031ee58a7bb46ab84f920056572a0731bb4569461b' 
  AND token = 'vEenzT4F07R6ZdmxKOSO+TUb6qAVtn1bo02Ddd5cUUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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