SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd618844bf097066f3e30f43b8b9805c55ec6a269ad36eb8feb60b100977a79bb' 
  AND token = 'tIF1oFLyPw5AEq/eaK0oj7cfqPVnxMbc7ThcovKxXh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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