SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c63bbf6e301125dca55c6bcf9338ea6e1a8c0fba1fd3a904490b661456356900' 
  AND token = 'CN3iVEMTzT0YChM/0YWrAmmhQ39kcnzLYqPMEdNcFB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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