SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b3ebecbb75b2d1791b6385ccc1c8250ebdcff1eb38437ba69f6fe81d1c609d8' 
  AND token = 'lggKEjJhfLUMSJ0tJ0W8bDEen+VSh1/O4r2oVmGECAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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