SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57a91cbd7f29a428d31a66e4b700a7ce6c1b21d49d8e61f027f5fb59930e8ef5' 
  AND token = 'QFZeJ9PxgjuDBySKnD34DGP+R6f3xSLK7ez8/TcL2sk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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