SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1460d969f243e7f3e2ba1d78f4f12d67efac1dab016f8226937785df3ce460c' 
  AND token = 'Ue/Y5RGEmLWBG25FkwZ0TNrYtCwubqbLF89+5UfHAiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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