SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f15027377883a28295fc08a2ab8a30f41579c10a2bd0815ae349aeefbfcad749' 
  AND token = 'ZoWegjHOYqxJjw6vxI9tXH2vp2WC1bVUiSem+0LeyKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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