SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b12954b032d8e2019a972c4ffa2ddac01cf81eef90082864088c8b4d59c8901' 
  AND token = '/zMgjLjSxt+qYgqhdwIEolUl0biJM9KOtSBA9WS6e2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}