SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2040266fc78ea5644649b68d72bfe74a643a030c95fb78f577855e38738dfc5' 
  AND token = 'RSHbzNzRvq1Xwj8+8xTuYtC6VHkWF/0JP7tGs0meaik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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