SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccd3f500f27ae816fa46962ee67eaa8882a14bbd8ba903030a7a6c845548d594' 
  AND token = '8bK6x0AH0kF3On/xtutWxnV8Xxj7Wz70thMJtPEnF9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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