SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfc06be8373b23726aad681257668d7a803f972c3af33ad0444414ce9cd2539c' 
  AND token = 'Qo8vXNM8LkvEBx2sBJuWZ9/BPznmDoqYg6Bq9sifZVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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