SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1923d7396c61d3d90c2796dd425374b17d4b9aa8245dd09ce7df2c195698cfd8' 
  AND token = 'kLFwZ7Y+giX2rq3+5j7xRJ1+X22VlqpZSY1ymuPRzrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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