SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d83216824ff6aeaec385bdefd976f87e5e7763b7a5b3041f48ec128046686d4' 
  AND token = 'jjuoBhj8hecWpLp5jLX45zorYUFH+gmIWdOL6pkKbyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

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