SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcecffec4ee769e24b6ce1efb4138584d073319bd5a9516c7e0af40bc14b8725' 
  AND token = 'I409vcs1GGHG5TPNk+9VynTv7tPaORzULoZlcRoHBWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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