SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'febefb35ce5aaecf5e3143b8b385c0ed6241d3c031c3940dd117c9666daae678' 
  AND token = 'Icvtkqv5pCitd4DZFUU0ItYpTxfScjMkp/zn/laTE34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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