SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2e8b459288c180c859affbf10c962cb08946b650e59d4ebf96de9b1adf4a1353' 
  AND token = 'jvxcDxbCXN2zBCckHSBwqNnFzk1NzS8gwVY/e+JNu1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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