SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '371529628d642aa9c2b7e31a566b3bb5567c2e7cab068330965d4cbadc4ce62f' 
  AND token = 'zK+po+m+whiIaD7WlEuwR7u0eOCsUKJHhrDOjBi83Xc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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