SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e6c0bfa956f41e203453e5158ce7d4cf093930a5f63ed574b452c504344e945' 
  AND token = 'ZOd/qHJ5WRWLSphKUbL07QwHdaheMBf9EOWjTItKpkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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