SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '389269e09a6b059c39488c02078ad5f574f013799dc33d2f10be6d35f38c4694' 
  AND token = 'fTutWm8ghqPkKwgy0waVUwSCINrhKe9h3HAMUM9m738=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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