SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '247fbae1e8b8fc508a85352ea49a6226ae5c42ddb771d1108cf6d3f47e2047d7' 
  AND token = '2HkzoT2375UzbIZexjdYp6WUoHK0bimFEbKMpxS8fuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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