SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eec972dafd6928d5bc1a53d5f3a5bd2cbe4b9adca4ed18fe4380fb05ce3a6b3e' 
  AND token = 'qnqzbFcE0aRvm2If0prL7ONQHQE3KlHx9jrsbjAPnZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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