SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2e95dad17c36209bf0e1399ea720bff3da5726d63d2dcf4f06efc8160c2e968' 
  AND token = 'Ze+nhekmS6zVeI4/x02XxWYtzK1pYQ94IE/ZCdbNVv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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