SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58fa97f25cff7e25283b69723166054f3e0563b06d36b9f2ad567e58499221c2' 
  AND token = 'JrBtE7lbLZT7qYQ4MV8NaoqN8RFWRo0sSnmsdNdYjAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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