SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41cad24746020bb22ada4a9bee7708272c4093bbf26898de6bcaedbd04ed3b68' 
  AND token = 'kruLHAV8nmQ84FTpJ29p1sHsIibGoA5xrPhlpfG4RRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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