SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28fa1e39ac03284f36612078efa83e50a5656a9de0a6d4d7eeb34450697b5432' 
  AND token = '1bnjcQzIXS1rJyTECr5vKRhRtjYhqGxiBVYSos4t2YY=' 
  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"
    }
  }
}