SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c7b858577f868dc5541e316225c5b00dd5817fa6570028a124117faa47f2299' 
  AND token = 'IrDmzAGcKGD5dke5wyZ1YnJWmowqz3InWaOblXxhGlo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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