SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c95d85833ba879f9870f279c293d01afc9d2b70647dfd9e4b683abc3445f675' 
  AND token = 'CiUk7TAlz+D/uvLSZhA+2zWpMPD/PM4STdjKdCvpT9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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