SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bc88c3dd2a2f2983e5832a0030c8cd4aad6beb9767699008180719d0fd342b6' 
  AND token = 'ngfL+i/QNc2YJLML12zj4yqeJGErVG+wpUoQaY7ZNQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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