SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f645d7f6b64bc127f2337da58d6204d0223d5e1861c7f41d64b532232619ed18' 
  AND token = 'Hw+7TuCc+RQ7OAhyvB5T0YOt1ly4tEtsH6pEvfmZOh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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