SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35ccb450bbc295b5d45323b89d612c07533475f303f5f382611cbb2bdcf2a816' 
  AND token = 'KNENLK1MOJG+8ygJz6VjVQWwe7h+upIAbKz4ImZY/qs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}