SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69937f939f900f55a3ab30befe26b718d4ae260fcacaf401dee14ab7e9c5aed5' 
  AND token = 'R1v9Ehtu39gDEcjijNvpijYcilqJg8Hn9PFljMBHCMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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