SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2efa922ae2edbffeea8026f15b3ccef3a380448ff3666701c85a5ee7f1b09339' 
  AND token = 'cu1tSgLwL2p/GylAe8qOojGfL/KYnzZ6VqYxv7aC6lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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