SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9418ef38aa44567ca522b4f2201047b6635305d7ebbfdafa67f46a3d2165833' 
  AND token = 'JUHIyQCBV7vQCtwbOxjp4SOyEQX8b6o4nSUiq83u1oY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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