SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65ff7ecaaacb127cd676922745a52fd271d7e2c0ec0f3fb0b9e72da8c4a5dcf7' 
  AND token = 'MaWeRA68hCBGDl59jt0nz+xpWq8iCWh3Dm6q8sS6WvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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