SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f09f739d5a647969f15e3a5e82d34ba44ffb61fab681a776b77d15248b5caa94' 
  AND token = 'SMVllaM7/wvWxOQqJMnuuooT1B9ysvNBA1PX1lWGbDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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