SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2e99a885cf497457fac7ec7aa3b55cc645d89994633f371492271640dc7be8e' 
  AND token = 'HheW0QDN3zvqhRqYOO+r2DKiyH/u8crt4efrqMRl600=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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