SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6536585b4dfdd8f35a8ff1fcd64aa624a87e32e1c9e0615027fa798c6d216ad5' 
  AND token = '3rIBln26zgQFcISGR98A+wpihm0VFWWZ+aTTXXliijI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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