SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0595782636bfb74a504e0a19b372242788ce47545a773ca77c1290f0987f9134' 
  AND token = 'EySrjHZrIDhpbUGtfqme8H5vTrkcko6XThGpTM830y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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