SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8b6ca493848ec0a60867c7899f1ee83693b26da4ffd49a96180d79f2a84f0e0' 
  AND token = 'RXHmiYG4saCE/DIJG9hOcCcmpIqAjbWVZs+jCezPOnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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