SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '907ed85c429d128fde4d632f953d8386be26283c46eafa1c86aa9f898eaf61d4' 
  AND token = '+6/UVIVhGpuRHYmrqVYPb1FVimvV00tasdFVYmlZeCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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