SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb1a1652346c8fdfb3a5908c79b62aa0441463e1b8c3dad436c483629af61965' 
  AND token = 'eMppEMDAQmAgv/Ao3Z9b+G1ifo0Z7kbwJx1GMVdJflY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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