SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b0ecd88a5e26948a19d728da9148ad254c41ef6096f17d1817a7c9ba8b6f930' 
  AND token = 'S8ZOT6OBUrX3q+nNmDUKNvn+PxCTuazjSJuG81hZgV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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