SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc470b74dbcf4646aed6767158dfaa00cf5a06d0f37852681b6b3495f3120d7c' 
  AND token = 'gHc2dZohedRzQ/iuDIsa9jsCZC22qLxIcW/SgcQEtNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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