SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24f5c930753de6759602745368ce822114aedfcfbd31fb999ce2a9b78c6cdb8c' 
  AND token = 'HPOIuWYfHSvxftuo6Lah/3Aw1kQXdOxBEEdscQS6zEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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