SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '697b387f1f3dfea46d8ff9f78687345ea881b0222f9604bd0dc6461560abb8f4' 
  AND token = 'mlo0Gxg62/OsDPw+sVQ3Yu0qA8BVw5CfxQAwSGWITZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}