SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'dfb8ff381b0a50feec04c24fcc1c65287a695a3f1c56f7011e3a008e0d37aa3d' 
  AND token = 'Xv0iT6c9UHo5yG7VLuOs/nivXdlT2gyiQ6ILP0r3GhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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