SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8578e387f35c853c2420e68a55f2e8ab62bae8924ed32b18e965156d91160a27' 
  AND token = 'fXprfqKp0Zl0PZQGyRVg3lPx9mdRHHxtfRvwDvBsAGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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