SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80384ab544edccda5ece369259ce68031a1ecc0e23102e278cacd7ce37d4e719' 
  AND token = 'U0Gc1nq3eVtCrGEo83GGLwWVjZiNdpUc3Wm/ZRVvRTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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