SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d0506778a07362b9858965b426efdcb0990c030071714e49ae6385e142b472c' 
  AND token = '12ROOLXLySB2SH+eurOYfUgxhhoEJB3BASdFzMO4Fa0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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