Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f326f5d2bdc8dbf40f9163937e792ecb0a21b235ee9ed8ec0d56daae0e953f8b' 
  AND token = 'Z7Rw1IqIwkCHCV5UjAnf7BKsHvUtmfefAhkN5Wa0Gog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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