SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9714b3d16b8ce2526f9dae187fa66cdd680f4d754b12d8dc31f52429ae7802d9' 
  AND token = 'kZCVJqvczL3n4gISA25GyU3pyuM+vWJk2Y9cKK/o13c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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