SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fedd522e7a066599906043a8da1a1b48d32f35c8eefd774d6d386e2fd7f796c3' 
  AND token = '14THWL8tqfN3OHekoHFSmI9y6Z5Cs84d52BR7EZQuXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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