SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e7473a538c9ed9e625e896f6441a9dd1028aece88778d697806d488ee10bb54' 
  AND token = 'Oc4DXcj974eDOqfmja5rOJl4SFMMASoELzTbEYIWCcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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