SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '262479d0ee4bc8c784a7ee7ce70322103f163512050809e00fbee5038abd498c' 
  AND token = 'Pozps5rvYAPMxfTGDe1Azw+qNcU7HnWC8DTECccSZZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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