SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c28b8565142972cd07aebd701d691fda9eeab53c9a4e66cc978651f37d36fb5' 
  AND token = 'mmPNxKhhkCROe4Ci7h/iZuXaVZFOUmGC0MxBQcWxWEk=' 
  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"
    }
  }
}