SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '471f337bd663437fdefebfafdf361154b075c3c728fbd874e59f2635a0bb8ecb' 
  AND token = 'cfNxmRdD3SvySG8I7nBROVmMhtc6TbgSw7U/TVsmV/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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